Abstract: Standing 157mm tall, the Xigmatek Thors Hammer heatsink tips the scales at 800 grams and has a rather boxy footprint of 120 x 116mm. It accomodates one or two 120mm fans that mount to the fins with special rubber vibration absorbing posts.

Once you
get past the dark nickel plated aluminum fins that overlap on multiple
levels, resembling some sort of future-fantastic piece of hardware from the
Dark Knight, what really makes the Xigmatek Thor's Hammer heatsink tick are
its stacked heatpipes. Yes, stacked heatpipes.
In other words, sitting just atop the row of 8mm exposed heatpipes at the base of the cooler is a second
row of 6mm diameter heatpipes.

As you likely know, direct contact heatpipes allow
heat energy to be efficiently conducted from the CPU to the aluminum fins
without first having to pass through a secondary heat spreader. By omitting the secondary heatspreader (typically a copper pad
heatpipes get soldered to), an entire layer of thermal joint resistance is removed from the
equation.

The additional layer of thin heatpipes on
top of the primary set, theoretically takes up the slack by filling in
the spaces in between. Stacked heatpipes; a viable thermal dynamics tool or ineffectual
fad? We'll see...

Standing
157mm tall, Xigmatek's Thor's Hammer heatsink tips the scales at
800 grams and has a rather boxy footprint of 120 x 116mm. It accomodates one or
two 120mm fans that mount to the fins with special rubber vibration absorbing
posts. No fans
are supplied with the Xigmatek S126384 heatsink, allowing users to
pick a high speed 120mm fan or ultra quiet model of their liking. For the purposes
of Frostytech's tests, a 120mm Mechatronics G1225S12B fan
that spins at 1500RPM will be used.

Xigmatek
opt for four 8mm diameter copper heatpipes swagged into the heatsink's
aluminum base block, as you can see below. In the space between each (consisting
of 2mm wide strips of aluminum), heat is conducted
to three additional 6mm diameter heatpipes.

Exposed heatpipe base heatsinks work best with
processors that have thick integrated heatspreaders and even heat distribution
over the entire CPU IHT surface area. They can encounter problems when heat
is localized too directly, such as if only one or two heatpipes receive the
bulk of heat from the CPU. It will be interesting to see what, if any, impact
the three additional copper heatpipes make.

Generally speaking, four 8mm heatpipes ought to have
sufficient capacity to conduct heat from a 150W Intel/AMD processor to the
aluminum fins of the Xigmatek Thor's Hammer heatsink. Adding more mass to the
base may simply 'sink' the heat to an area with little or no airflow
passing by it.

If the HDT-S126384 heatsink is designed properly, it
should be more efficient to move the heat energy to the thin aluminum fins
which have significant surface area, than conduct it via relatively inefficient
4.5mm tabs of aluminum to a small 83x61mm triple-fin tab (see picture
above) under the main cooling fins.

The nickel plated aluminum fins on the Thor's Hammer
heatsink have overlapping leading and trailing edges to break up the profile of
the tower where impingement airflow is concerned. This can make it easier for
low pressure airflow to pass through the fins. Given the option between raw
aluminum fins and nickel plated fins, Frostytech would opt for the former.

The notches
pictured above are for the rubber tabs to latch into. Xigmatek
rely upon the same little rubber posts for all of its
heatsinks. Personally, we prefer wire fan clips with some sort of elastomer
between the fan and fin tower.

Heatsink Installation

Xigmatek's S126384 Thor's Hammer heatsink is compatible with Intel socket 775/1366 and AMD socket
754/939/940/AM2/AM3 processors. The heatsink comes with one metal support bracket for the back of Intel 775/1366 motherboards
that requires the board to be removed from the PC case for installation. Upper
metal clips make subsequent CPU swaps more straightforward.

AMD platforms make use of the standard AMD
heatsink retention cage. A simple cam-lever-arm clip applies the
necessary claming force to keep the HDT-S126384 heatsink in position. Tool
free installation is always nice, but given that this heatsink weighs upwards of
800grams, a slightly more
robust AMD mounting bracket would have been wise...

Instead of wire fan clips, Xigmatek
opt for rubber vibration absorbing posts which tie into the fins to firmly hold a 120mm
fan in position. One or two 120mm fans can be mounted to the heatsink (fan
not included).

FrostyTech's Test Methodologies are outlined in detail here if you care to know what equipment is
used, and the parameters under which the tests are conducted. Now let's move
forward and take a closer look at this heatsink, its acoustic characteristics,
and of course its performance in the thermal tests!